Field of the Invention
The present disclosure generally relates to image forming and, more particularly, to an image forming apparatus, an image forming method, a storage medium, and to a technique for reducing excessive amount of color materials consumed in an electro-photographic image forming apparatus.
Description of the Related Art
Conventionally, in a field of an image forming apparatus employing an electro-photographic method, there has been an increased demand for reduction in consumption of toner. For example, Japanese Patent Application Laid-Open No. 2004-299239 discusses a technique for saving consumption of toner by lowering exposure intensity of an image region having a certain size.
Further, it is known that a phenomenon in which an amount of development toner is increased at an rear end portion of a latent image than in a central portion thereof occurs in the electro-photographic image forming apparatus. The above phenomenon is referred to as a sweeping-effect. With respect to the sweeping-effect, Japanese Patent Application Laid Open No. 2007-272153 discusses a technique in which correction processing is executed on image data to correct the sweeping-effect by adjusting an exposure amount.
In addition to a problem of the above-described sweeping-effect, there is a known phenomenon in which an electric field is concentrated on a boundary between an exposure portion (i.e., electrostatic latent image) and a non-exposure portion (i.e., charged portion) formed on a photosensitive drum to cause toner to be excessively adhered to an edge of an image. This phenomenon is referred to as an edge-effect. The edge-effect may occur in concurrent with the above-described sweeping-effect. Therefore, with respect to an image portion in which the sweeping-effect and the edge-effect have occurred concurrently, correction processing suitable for the respective effects has to be executed in order to lower the exposure intensity to reduce excessive toner. If the correction processing suitable for the respective effects cannot be executed, degradation of image density may occur and cause image quality to be deteriorated.